The present invention relates to a production quantity adjusting apparatus for corrugators of a type which produces corrugated board by facing a corrugated core board with a liner or liner-board on one or both sides thereof.
The corrugated board is manufactured by using raw material boards in roll form as raw materials, and the raw material boards include a raw core board having corrugations of the corrugated board and a liner applied to each side of the core board. In a corrugator, a portion which applies a liner to a core board to manufacture a single-faced corrugated board is called a single facer section and another portion which applies a liner to the single-faced corrugated board is called a double facer section. The single facer section and the double facer section are generally arranged in line, and in particular the length of the single facer section ranges from a minimum of 50 m to a maximum of over 100 m. As a result, if the timing of changing the formation of raw material boards is inaccurate, it is not unusual that a considerable quantity of the raw material boards will be wasted.
With a known corrugator of this type, a change in the formation of raw material boards or lot changing is accomplished manually by the operator or alternatively a mark made of a silver paper or the like is attached to each raw material board just prior to the lot changing and the materials are made to run in this condition so that the residual amount of the raw materials existing between the place of feeding the raw materials and the place of finished product is measured to ensure accurate lot changing. A disadvantage of the former is that it is difficult to ensure the desired accuracy. The latter method is also disadvantageous in that while there is no problem with respect to accuracy, the method is not fit for use with small lots, and moreover since the materials are run with attached marks, the sheet portions having the attached marks must be rejected, thus causing a loss of sheets each time the residual quantity is measured. Particularly, the production process of the corrugator involves the manufacture of a wide variety of products ranging from several thousands to several tens of thousands of types resulting in the use of raw material boards diversified in width, basis weight, paper quality, etc., and there has existed a need for an apparatus which accomplishes the desired changeover of raw material boards or lot changing without any waste, thus ensuring efficient production.